In this study, the potential to improve the energy efficiency of lighting systems at Melbourne University was assessed. The cost effectiveness of different lighting technology alternatives was also calculated. Electricity used by existing 1.2 metre fluorescent lighting fixtures and four energy efficient lighting technology alternatives was compared. Relative to the existing system, installation of the four lighting technology alternatives would result in energy savings of 13.9%, 20.5%, 24.4% and 64.9%, respectively. If the technology alternative that saved the most electricity was installed, carbon dioxide emissions associated with the University's electricity use would be reduced by about 10%. Economic analysis shows that overall, none of the four technology alter-natives are cost effective, although fine scale analysis shows that one technology alternative is cost effective in two out of the five room categories that were examined. Three barriers to the cost effective installation of energy efficient lighting technologies at Melbourne University are identified: (a) low lighting system operating hours, (b) the low cost of electricity and (c) the high cost of energy efficient lighting components.